Towed implement that compensates for unbalanced loads caused by offset centre of gravity

Abstract

A towed agricultural implement including a first headstock element for connection to a towing vehicle, a second headstock element supporting a chassis member provided with a plurality of working implements, a pivot pin for connecting the first headstock member and the second headstock member and defining a horizontal axis of rotation between the first headstock member and the second headstock member, in which the second headstock member has a lateral centre of gravity offset from the axis of rotation. A compensating structure is provided between the first headstock member and the second headstock member to offset the unbalanced loads caused by the lateral centre of gravity being offset from the axis of rotation.

The invention claimed is: 
     
       1. A towed agricultural implement comprising:
 a chassis member carrying a plurality of working elements; 
 a first headstock element for connection of the agricultural implement to a towing vehicle; 
 a second headstock element supporting the chassis member; 
 a pivot pin connecting the first headstock element and the second headstock element and defining a horizontal axis of rotation between the first headstock element and the second headstock element, 
 wherein the chassis member carrying the plurality of working elements extends transverse the horizontal axis of rotation such that the chassis member carries at least one of the plurality of working elements on a first side of the horizontal axis of rotation and at least one of the plurality of working elements on a second side of the horizontal axis of rotation opposite the first side, and wherein the towed agricultural implement has a lateral centre of gravity offset from the horizontal axis of rotation; and 
 a biasing member acting between the first headstock element and the second headstock element, wherein the biasing member acts to compensate unequal loads resulting from different working elements causing a change in the centre of gravity so that each side of the towed agricultural implement is subject to equal bearing loads. 
 
     
     
       2. The towed agricultural implement of  claim 1 , wherein the first headstock element comprises first and second walls, a generally vertical member extending between the first wall and the second wall, the generally vertical member comprising a tubular support between smaller and larger portions of the generally vertical member, and the second headstock element is secured to the chassis and comprises a central web separating front and rear panels each provided with bushings, the pivot pin extending through the tubular support and the bushings. 
     
     
       3. The towed agricultural implement of  claim 2 , wherein the central web also separates first and second side walls, the second headstock element further comprising a pin extending between the first and second side walls, a stop plate located in a predetermined position on the pin, an abutment plate mounted on the pin for abutting the smaller portion of the first headstock element, wherein the biasing member is located on the pin between the stop plate and the abutment plate and wherein the stop plate is adjustable on the pin. 
     
     
       4. The towed agricultural implement of  claim 2 , wherein the biasing member comprises an elastic spring. 
     
     
       5. The towed agricultural implement according to  claim 4 , wherein the elastic spring is a helical spring. 
     
     
       6. The towed agricultural implement of  claim 1 , wherein the plurality of working implements comprise cutting units for a mower. 
     
     
       7. The towed agricultural implement of  claim 1 , wherein the plurality of working implements comprise cutting units and a conditioner for a mower.